user
Write a response that appropriately completes the request.

### Instruction:
Explain how the genetic variability of each species can contribute to evolution.

### Response:
assistant
Genetic variability is an important factor in evolution. Genetic variability occurs when individual members of a species differ in the alleles they possess. This variability can arise through mutation, the accumulation of random errors as genes are copied and passed on from one generation to the next. As new alleles are passed on, some of them may confer an advantage to the organism that possesses them. This can cause those beneficial alleles to become more common in subsequent generations, gradually leading to evolutionary change in the species as a whole. The more genetic variability that exists within a species, the more potential there is for these beneficial alleles to arise and for evolution to occur. In this way, genetic variability is one of the driving forces behind evolutionary change.